Sun visors for vehicles sometimes incorporate a so called slide on rod (SOR) function which allows the sliding of the screen along the rod to provide an additional covering area when the sun-visor is placed at a lateral position, by the side window of the vehicle.
SOR sun visors comprise a carrier or slider that holds a detent clip that allows rotational movements to the screen around the rod, predefining at least a preferred angle position. The carrier is housed in an inner guiding channel of the screen that blocks the relative rotational movement between the carrier and the screen, but allows guided longitudinal movement such that the screen can slide over the carrier from a non-extended position to an extended position. The guiding channel can be provided by the inner structure of the screen in twinshell sun visors or by an additional guiding tube incorporated inside the screen.
The guided movement of the screen requires a free-play compensation between the carrier and the inner channel to assure a regular and steady effort for sliding the screen over the carrier.
It is also important to have a run-end retention of the guiding movement of the screen to provide some extra effort at the time of detaching from or clipping to one run-end position, to have a notice that the sun visor is at such run-end position.
It is known in the art the use of flexible plastic retention clips fitting in corresponding retention housings, placed in the slider and the screen respectively to provide a run-end retention of the sliding movement. The retention is obtained by the flexibility of the plastic retention means.
JP-2014-121919-A is an example of this kind of flexible retention. It describes a protuberance 220 comprising a hooking portion that engages and disengages with the engagement parts 16 and 17 of the slider. The protuberance 220 flexes and deforms, such that the restoring force in the engagement direction is imparted by the elasticity of the side face 103 of the screen, being noticed by the user.
WO-2014132569-A1 is another example of flexible retention. In this case the patent describes an engaging claw 36 which can be flexed in a direction orthogonal to the axial direction. The engaging claw 36 is engaged with the axial end portion 17f of the accommodating space 17 when the main body 22 abuts on the axial end of the accommodating space 17 by sliding the shield 16.
In U.S. Pat. No. 7,798,551-B2 the locked position is define by the sizes of the protrusions and engagement holes, defining with these dimensions the suitable insertion resistance, and fixing in this manner the sun visor body at both ends.
A first problem of these plastic clips working at flexion is that they suffer from permanent deformation, material ageing, and they are sensible to temperature, what means that it is not possible to guarantee its functional durability in all kind of conditions and through the time.
Furthermore, as the retention clips are arranged in the carrier and the housing are in the screen, any possible misalignment between the screen and carrier (due to free-play and manufacturing tolerances) provokes misalignments between the retention clips and their corresponding housings in the screen. This implies a variable retention force and the possibility of unexpected detachment or even a retention attachment not being possible, or even permanent damages.
To solve the problem of misalignment between the sun visor screen and the carrier, and the absorption of any free-play inside the guiding profile, in some sun visors the carrier comprises floating sliders which, in addition, improve the sliding efforts and noises.
One example of this is described in U.S. Pat. No. 8,905,457-B1 that describes a floating slider with means for limiting the stroke of the sliding movement, but no retention is used for maintaining the run-end position.
Another example of sun visor with a floating slider is described in U.S. Pat. No. 7,926,864-B2. In this case the sun visor also shows flexible retention means comprising flexible tongues 8 disposed in two plugs 7 at the ends of the guiding profile 4 for fitting in the corresponding engagements in the slider 2. This flexible retention means have the same problem described previously for the plastic clips working at flexion.